Surfacing and polishing



Sept. 26; 1933. F. BETRANCOURT 1,928,196

SURFACING AND POLISHING Filed Feb. 17, 1933 J! I, 11 III-UM ,9 I /0 26 l I 2 6 l] H 1 I INVENTGR F52 TUNE BE'TPAM: OI/ET ATTORNEY 0 increase the cost of the special skill in handling'or in adjustment by Patented Sept. 26, 1933 -UNITED STATES PATE NT OFFICE SURFACING AND POLISHING Fortune Btrancourt, Pisa,

Italy, assignor to Societe Anonyme Des Manufactures Des Glaces & Produits Chimiques De Saint-Gobain,

Chauny & Cirey, Paris, France 9 Claims.

This invention relates to surfacing and polishing and it particularly relates to methods and apparatus of surfacing and polishing plate glass.

In continuous surfacing operations for glass and particularly in glass polishing and surfacing machines the glass plates to be surfaced are carried on tables or movable supports beneath driven surfacing units. The surfacing or polishing units usually include runner arms, usually joined together to take the form of a spider, which spider is rotated by suitable driving means. The runner arms of the spider carry polishing blocks by universal connections.

Since the centers of gravity of these polishing blocks are located a substantial distance below thecenter of the universal support, the action of centrifugal force incident to the rotation of the runner arm or the spider at a relatively high rate of speed has atendency to tilt and move the center of gravity of the block outwardly. This tilting effect increases if the support of the block is removed from the center of rotation of the runner arm or spider. As a result, the polishing cloth or felt will press more lightly on the glass surface over the outer half of the area which it covers than over the inner half.

Due to this centrifugal and resultant tilting action, the polishing efliciency of the tilting block is substantially reduced as compared to .a block which presses evenly on the surface of the glass throughout the area thereof, and the extreme margins of the sheet of glass are not as well polished as the body of the sheet of glass inside such margins. This effect is particularly objectionable as the support for the block is farther removed from the center of rotation of the spider. v

An object of the present invention is to' providea surfacing and/or polishing means and method in which the polishing efliciency and/or surfacing efliciency will not be reduced due to centrifugal force and in whichan even surfacing' and polishing will be obtained over the entire area contacted with the polishing or surfacing blocks, even though the blocks be supported at substantial radial distances from the center of rotation, in spite of relatively high strong centrifugal action and without the utilization of complicated arrangements which apparatus, or require the operators.

Another object is to design a plate glass surfacing machine in which the tendency of the surfacing block to tilt under the action of censubstantially trifugal force will be overcome and in which the block will be caused to exert a substantiallyuniform pressure on the area of the glass with which. it contacts without being particularly affected by the centrifugal force exerted.

Other objects will be obvious and will appear during the course of the following specification.

In accomplishing these objects it has been found particularly desirable to provide a loading for the outer side of the surfacing block or plate, so that the tendency of the plate to tilt is overcome, and it is a particular object of the present invention to so construct the apparatus and to. so. apply this load that it will vary with the centrifugal force to overcome the increased tendency to tilt the block at high rotational velocities.

It is also a further particular object to arrange these" variable loads and to so support them independently of the polishing block itself so. that, a greater weight will not be carried upon the support for the polishing block and so that there will not be any undue stress, upon the pivotal or universal connections for said block.

' In accomplishing these last-mentioned objects it has been found desirable to support or to con-. met the variable loading mass'or weight. to the spideror runner arm adjacent to the point, of support of the block. The weight isfpreferably caused to act upon the outer edge of the surfacing block to prevent. the same from tilting. The weight or load should be so arranged that it will exert a greater force to counteract the tilting with higher revolutional speeds than with lower revolutional speeds.

The above and other objects will appear more clearly from the following detailed description,

when taken in connection with the accompanying.

drawing, which illustrates a preferred embodiment of the inventive idea.

In the drawing, the. figure diagrammatically shows a vertical section through the end of a. runner arm or spider and through a polishing block carried thereby.

Referring to the drawing the table 1 carries a plate or sheet of glass 2. The table 1 is movable on a track (not shown) extending beneath the runner, one of whose arms is indicated at 4.

The arm 4 carries the spindle 5 which is universally connected to a block '6. The block 6 has a body 7, as for example of cast iron or other suitable material, provided with a polishing face 8 of felt or cloth, which may be rigidly attached to the body 7.

The spindle 5 projects upwardly through an opening 9 in the boss 10 of the runner arm 4 and it is threaded at its upper end as indicated at 11. Upon the threaded end 11 is screwed the nut 12 which contacts with the top of the boss 10.

The spindle 5 is provided with a peripheral projection 13 adjacent its lower end 14. This peripheral projection may be fitted into the slot or socket 15, which is centrally positioned in the body 7 of the block 6. It will be noted that the socket 15 isprovided with an inwardly turned shoulder 16 which contacts with the peripheral projection 13 of the spindle 5 to prevent the block from falling away fromrthe spindle, or to prevent the spindle from being lifted out of the block. At the same time the cavity 15 is sufficiently large in respect to the peripheral projection 13 and the end 14 of the spindle 5 that substantially universal movement is permitted between the block 6 and the spindle 5.

Contacting with the outer edge 20 of the block fi is the rider 21 provided with a wheel 22. This rider pressesdownwardly on the outer portion 20 of the block, which tends to tilt upwardly under the influence of the centrifugal'force. The roller 22 is carried in the clevis 23 of the sliding pin 24, which is received in the opening 25 in the boss 26.

Fitted into the opening 25 is a bearing sleeve 2'7 which contacts and closely fits about the pin24.

The upper side of the pin is provided with a plate I element 28.

V The arm 29 of the counterbalancing arrangement 30 is arranged to press on said plate element 28 of the rider 21. The counterbalancing arrange- 1 ment 30 is pivotally connected at 31 to an extension 32 of the supporting arm 4. Itincludes a bell crank lever, which is provided with the short arm 29', the outer end of which contacts with the plate 28 at the top of the pin 24 and with a relatively long arm 34 extending substantially vertically upwardly and slightly outwardly and provided with an adjustable sliding weight 35 thereupon. k V g I In operation, the center of gravity of the block ,7 will be substantially below the point of universal support in the socket 15 so that as the arm 4 rotates the centrifugal force will tend to cause the block to'assume a tilted position with the outer edge" of the block lifted. Under the action of the centrifugal force, the weight or mass 35 50 will also be thrown outwardly, pressing down on thearm 39and on thepin 24, whereby the up ward'tiltin'g tendency of the outer portion of the block 20 will be overcome. Preferably; the weight 35 is adjusted so that the pressure it will exert upon the pin 24 and upon the'outer' edge 20 of the block will be proportional to the centrifugal force, tending to cause upward tiltingi This is particularly advantageous inasmuch as the downward pressure exerted by the weight or mass 35-will at all times overcome the tilting tendency regardless of the speed at which'the arm' may be rotated, the downward pressure uponthe edge 20 upon the plate G'being greater at higher speeds than atlower'speeds.

It is thus apparent that the polishing efficiency of theblock will not be reduced, even though it the surface of the glass throughout the operation. ,As a result, an even polishing-will be obtained, regardless of the speed of rotation of the arm 4. In addition, by pivoting the counterbalancing mechanism 30 upon the arm 4 no addi-' tional load isplaced upon the block 6, nor the spindle 5 so that no elaborate constructions are necessary to overcome excessive strain and stresses.

It will be noted that the pressure of the weight 35 exerted upon the outer edge of the block 6 through the roller 22 will not prevent free rotation of said block.

It is apparent that the present invention may also be utilized for polishing other materials, such as plates of marble, sheets of plastic material, and so forth, and also that the present invention has a broad applicability to similar devices for utilization in other connections than polishing or surfacing.

The device is capable of many modifications, only one of which is described here by way of example. It is understood that the details of construction may be readily changed without avoiding the scope of the invention.

What is claimed is:

1. In combination, a surfacing block, a universal joint support for the block permitting it to tilt and rotate and located above the center of gravity of the block, a runner arm for supporting said universal joint support, and counterbalancing' means independently pivotally mounted upon said runner arm and adapted to be moved outwardly by the centrifugal force when said support is moved in a circular path around the center of rotation.

2. In combination, a surfacing block, a universal joint support for the block permitting it to tilt and rotate and located above the center of gravity of the block, a runner arm for supporting said universal joint support, and counterbalancing means including a bell crank lever with a vertical arm carrying a weight independently pivotally mounted upon said runner arm and adapted to be moved outwardly by the centrifugal force when said support'is moved in a circular path around the center of rotation.

3. In combination, a surfacing block, a universal joint support for the block permitting it to tilt and rotate and locatedzabove the'center of gravity of the block, a runner arm for supporting said universal joint support, and counterbalancing means including a rider contacting with the outer portion of said block, a pivotally supported weight carried by said arm and a connection to cause said weight to press on said rider, said weight being adapted to be moved outwardly by the centrifugal force when said support is moved in a circular path around the center ofrotation.

'4. In, combination, a surfacing block, a universal. joint support'for the block, permitting it to tilt-and rotate and located above the center of gravity of the block, a rotating spider for carrying said support, and counterbalancing means mounted for horizontally pivotal movement on said spider adjacent the center of support of the block and adapted to be moved outward by centrifugal force.

5. In combination, a surfacing block, a universal joint support for the block, permitting it to tilt and rotate and located above the center of gravity of the carrying said support, and counterbalanclng means including a pivotal weight mounted for horizontally pivotal movement on said spider adjacent the block, a rider contacting with the outer portion of the block and a connection to cause said weight to press downwardly upon said said weight being adapted to be moved outrider,

block, a rotating spider for ward by centrifugal force and to press downwardly upon said rider with a force varying with the rotational speed of the spider.

6. In combination, a surfacing block, a universal joint support for the block, permitting it to tilt and rotate and located above the center of gravity of the block, a rotating spider carrying said support, and counterbalancing means including a bell crank lever carrying a weight mounted for horizontally pivotal movement on said spider adjacent the center of support of the block, said weight being adapted to be moved outward by centrifugal force.

7. In combination, a support arm, a surfacing block rotatably and tiltably mounted upon the support and a weight also secured to the support to move outwardly under the influence of the centrifugal force and provided with a connection to press downwardly upon the outer portion of the block.

8. In combination, in a surfacing or polishing machine, a rotating supporting spider provided with an outwardly extending runner. arm, a surfacing block having a universal connection to said arm, said universal connection permitting said block to tilt and rotate and being located above the center of gravity of the block, and counterbalancing means to prevent tilting of the block during rotation of said arm, said counterbalancing means including a sliding pin with a roller contacting the outer portion of the block and having a bearing in the runner arm, a bell crank lever pivotally supported upon said runner arm provided With an outwardly extending arm contacting with the top of said pin to press downwardly thereupon and through said pin upon the outer portion of said block and also having an outwardly and upwardly extending arm provided with an adjustable weight.

9. In combination, in a surfacing or polishing machine, a rotating supporting spider provided with an outwardly extending runner arm, a surfacing block having a universal connection to said arm, said universal connection permitting said block to tilt and rotate and being located above the center of gravity of the block, and counterbalancing means to prevent tilting of the block during rotation of said arm, said counterbalancing means including a bell crank lever pivotally supported upon the top of the runner arm and provided with an upwardly and outwardly extending arm, an adjustable weight on said upwardly extending arm, and a connection from said outwardly extending arm to the outer portion of said block to enable the centritugal pressure of said weight to be transmitted to said block.

FORTUNE BETRANCOURT. 

